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Broadcast power has been a staple of science fiction practically forever. The main problem with it is to get the power density at the power receiver up to a reasonable level. The power density required is going to be in kilowatts per square meter (kW/m^2) range. Of course the power density used by the various communications devices we are familiar with run more in the microwatts per square meter. If we lived in an environment where the power density was up in the kW/m^2 range it would be something like living in a microwave oven. I don't think I want to move into a microwave. The only source that gets into that general range is sunlight. There is just no way to get larger amounts of power out of intentionally transmitted signals.

Bill Gill

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C is not the speed of light in a vacuum.C is the universal speed limit.

And by the way, if you coated the walls and roof of your house with antennae you would lose all reception of the signals you were using inside the house. That would be kind of hard on you if you were depending on your cell phone.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

The picture of the two inkjet printed antennae that the guy is holding in the original URL... do not tally with the words 'harvested TV and radio signals'.He is holding an enlarged print-outs of two Fractal wide band aerials.They might be able to power the latest military microchips, but to report (transmit) back to a base, as to what frequencys the 'enemy' was using, would require an extra TX chip hooked into a proper power source.The original blurb tends to state that radio waves in the air can be used to harvest various electronic devices.Maybe... but not by using those Fractal aerial, 'sucking' micro-watts from VHF radar, or similar installations.Yes, the minute RFID devices that Hitachi manufacture, could be powered using Fractal aerials....since they are virtually invisible, being about 0,05mm X 0,005 thick.Used I believe embedded in paper packaging, and/or high value Banknotes. Then again RFID chips are interrogated using a high frequency power source when taken out of a fixed area. So no point in using RFI chips...so I assume the military do have an as yet unknown use for these Fractal aerials. The only type of aerials that can take RADIO power out of the air.. is in the medium or longwave wavebands, put out by the normal radio stations.For instance you can build a Crystal Set, they require NO power whatso ever and this allows you to listen to dozens of radio stations around the world. (Useful during a National Emergency?)Building a good quality Crystal Set using a full wave circuit, and schottky diodes or similar and specialised csapacitors (prehaps a 1-2 Farad 3volt cap) will give you enough power to run a Crystal Set PLUS an amplifying chip that uses very little power, like a ZL70250 radio chip. Years ago crystal sets used earphones of about 2000 ohms resistance, but today one can use a pair of Ceramic earphones of at least a million ohms (barium titanate?)which put out a loud enough sound, that you could attach a horn to.

Years ago crystal sets used earphones of about 2000 ohms resistance, but today one can use a pair of Ceramic earphones of at least a million ohms (barium titanate?)which put out a loud enough sound, that you could attach a horn to.

It has been a long time but I have seen crystal sets that worked with a horn antenna. The volume wasn't exactly room filling, but it was possible to hear them. I don't know how strong a signal you needed to hear it on the horn, but it was there.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

And by the way, if you coated the walls and roof of your house with antennae you would lose all reception of the signals you were using inside the house. That would be kind of hard on you if you were depending on your cell phone.

not being bombarded with all those microwave , radio , tv , and whatever signals we dont even know about ... yet.

I think that would be great!

its a good thing that you could mount a antenna outside your house to capture the signals that you want or need to capture isnt it.

_________________________
3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.

its a good thing that you could mount a antenna outside your house to capture the signals that you want or need to capture isnt it.

But then you would need to couple the antennae from outside the house to more antennae inside the house to rebroadcast the signals. And in the meantime you wouldn't be getting enough power from the antennae on the walls and ceiling to power the broadcast unit in the house.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

you wouldn't be getting enough power from the antennae on the walls and ceiling to power the broadcast unit in the house

could you show that there would not be enough power?

afterall the article states that the signals would power devices and a broadcast unit is a device.

its just that you would have hundreds of thousands of antenas capturing the energy from the signals outsideand you claim that there wouldnt be enough power to power a single broadcasting unit inside , when the devices they are talking about are for the most part broadcasting units such as cell phones...

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3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.

Remember, we are talking about microwatts per square meter as the signal levels we are talking about harvesting. I didn't read the article, but I am sure that they were not talking about powering transmitters that would have to generate as much as 100 mW of RF power. What one of the other posters mentioned was that they were talking about powering extremely low power device.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

Scavenging experiments utilizing TV bands have already yielded power amounting to hundreds of microwatts, and multi-band systems are expected to generate one milliwatt or more. That amount of power is enough to operate many small electronic devices, including a variety of sensors and microprocessors.

And by combining energy-scavenging technology with super-capacitors and cycled operation, the Georgia Tech team expects to power devices requiring above 50 milliwatts. In this approach, energy builds up in a battery-like supercapacitor and is utilized when the required power level is reached.

well , it looks as if they expect to get as much as 50 milliwatts.

.050 Watts

a home that has a roof with a surface area of 15 meters x 30 meters is 450 sq meters and .050 watts per sq/meter means you could get apx 22.5 Watts from the roof alone.

and these could be located under your solar pannels. LOL

Quote:

I am sure that they were not talking about powering transmitters that would have to generate as much as 100 mW of RF power.

does your cell phone generate 100 mW of RF power?

Quote:

What one of the other posters mentioned was that they were talking about powering extremely low power device.

thats what they were talking about , but why stop there when the area is available to put the antennas on a homeand power your tv , your dvd , and with a storage system storing wattage 24/7 why not all your appliances as long as there is enough stored wattage.

I have a computer that uses only 50 watts , so in the future we can expect even smaller lighter less energy consumming products ( due to the shipping weights from china )that could replace the heavy bulky appliances we now use.

plus you can buy refrigerators that use a fraction of what a normal refrigerator uses.

etc..etc..etc...

so you can downgrade it all you want , the fact is that as long as it can produce enough to reduce the energy demand it will fade away.

and they are just printing the entire device on a sheet of plastic , the antenna the circutry and all.

knowing they can do that in America with a printer tells me that we can print our own appliances in America.

and with that said , why couldnt you have a antenna that captures movies and data etc...etc...

this really could turn into something big if it wernt for the greedy rich people who have already spent all their money on chinas economy.

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3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.

A note on required power levels for an in the house transmitter. My LinkSys wireless router transmits at 18 dBm,(decibels above 1 mW). That is about 63 mW. That is more than I would expect from any kind of RF harvesting device.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

Physorg.com has an article today about harvesting energy from radio fields in the air. Follow the link to the story.

Originally Posted By: physorg.com

Engineers demoing the two devices say electricity produced by the WiFi version is in the microwatts at a distance of just 10cm from the source, not a lot of course, but enough to power a small sensor or tag, they say.As for the terrestrial version, they were able to generate about 1.2mV and 0.06µW of power inside the exhibition hall, where the video was made, at the Tokyo Big Sight

I don't see that powering a house very well.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.

The signals received were from a digital terrestrial broadcast sent from the Tokyo Tower which was about 5.5km away.

I just wonder how many of the pads would fit into a 5.5kmcircle?a few billion perhaps?

see , free energy no matter how you see it.

the perimeter of that 5.5 km circle alone is 34,500 meters

the units he is holding look like they are apx 15 cm x 15 cm = 225 cm^2

1 meter has 10,000 sq cm = 44 devices in each sq meter just along the perimeter.

34,500 x 44 = 1,518,000 devices touching the perimeter.

the area of the 5.5 km circle is 95 million sq meters.

95,000,000 x 44 = 21 billion devices

21,000,000,000 devices x .0012 volts = 25,000,000 volts !!!

the article said that the device was able to produce .006 watts at a distance of 3-4 km from the tower.

21,000,000,000 devices x .006 watts = 126,000,000 watts

so it looks like the wattage produced gets higher the closer you get to the tower , I figured that would be the case.

I wonder if the radio station uses that much wattage when broadcasting?

and I would be willing to bet that the radio signals dont stop at the 5.5 km range either !!

so now we know that free energy is available in this type of device at least , that brings us back to the UGT plastic printed devices , put them everywhere you can find room for them and no more power plants at all.

just a lot of printers.

and of course more jobs and growth than any country could handle alone.

AHEM , muhahahaha...

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3/4 inch of dust build up on the moon in 4.527 billion years,LOL and QM is fantasy science.

the article said that the device was able to produce .006 watts at a distance of 3-4 km from the tower.

No, it said the device was able to produce .006 microWatts, that's .006 millionths of a watt. Also keep in mind that it is rare for a broadcast station to transmit over 50 kW, so no matter how you work it that is all you could get out of it and then you would be using up all the power for your power receivers, and leaving nothing for the communications receivers that it is aimed at.

Bill Gill

_________________________
C is not the speed of light in a vacuum.C is the universal speed limit.